Answer:
In a system, the substitution method is one of the 3 main ways to solve a system and can be very efficient at times.
<u>Skills needed: Systems, Algebra</u>
Step-by-step explanation:
1) Let's say we are given two equations below:

We can use substitution here by substituting in for
in the second equation. This means we put in
for
in the 2nd equation so we only have
variables in the equation, allowing us to solve for
.
2) Solving it out:

We essentially substitute in that value as seen in step 1. Steps 2 and 3 are just simplifying the left side and allowing for us to solve. Step 4 is where we divide by -16 on both sides to solve for x. Step 5 and 6 show us solving for y using the value for x. We get 
<h2>
Hello!</h2>
The answer is:

<h2>Why?</h2>
To solve the problem, remember to set your calculator in "degree mode"
So, we are given that the angle A is equal to 68°
So, we have that:

Hence, we have that:

Have a nice day!
Using the combination formula, it is found that Julia can take 15 combinations.
<h3>What is the combination formula?</h3>
is the number of different combinations of x objects from a set of n elements, given by:

For this problem, 4 students are taken from a set of 6, hence the number of combinations is given as follows:

More can be learned about the combination formula at brainly.com/question/25821700
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